Some older Samsung Electronics Co smartphones and tablets could be taken off store shelves in the United States after the U.S. Trade Representative opted not to reverse a ban ordered because the devices infringe Apple Inc patents.

The decision is the latest step in a patent battle across several countries as Apple and Samsung vie for market share in the lucrative mobile industry. Samsung and Apple are the No. 1 and No. 2 smartphone makers globally, respectively.

Neither the U.S. International Trade Commission (ITC), which made the patent ruling, nor the U.S. Customs and Border Protection, which would enforce the ban, has spelled out which of Samsung's many devices will be affected.

Despite the ban, AT&T expected to continue selling Samsung products. "This decision will not affect our ability to provide the latest Samsung devices," said Marty Richter, a spokesman for AT&T.

The ITC said on Aug. 9 that some smartphone and tablet models made by South Korea's Samsung infringed on Apple patents, and banned their importation or sale.

U.S. Trade Representative Michael Froman had 60 days to overturn the ban, as he did in a recent case where Apple was found to have infringed on a Samsung patent, but decided not to.

"After carefully weighing policy considerations, including the impact on consumers and competition, advice from agencies, and information from interested parties, I have decided to allow the commission's determination," Froman said in a statement.

A Samsung spokesperson said: "We are disappointed by the US Trade Representative's decision to allow the exclusion order issued by the US International Trade Commission. It will serve only to reduce competition and limit choice for the American consumer."

Apple filed a complaint in mid-2011, accusing Samsung of infringing its patents in making a wide range of smartphones and tablets.

The ITC ruled that the Samsung devices infringed on portions of two Apple patents on digital mobile devices, related to the detection of headphone jacks and the operation of touchscreens.

Samsung has said its newer models incorporate features that work around disputed technology, and that those changes have been approved by the ITC.

When the ITC issues exclusion orders, they generally do not have model numbers of devices but are broadly written, said Jamie Underwood, an ITC patent expert with the law firm Alston & Bird, LLP.

Both companies have likely been lobbying aggressively, with Apple pushing for a larger number of Samsung models to be banned and Samsung arguing for fewer, she said.